1. Technical Field
The present invention is directed to permanent establishment of an immortal line of human fetal glial cells, more particularly of glial cells which inter alia, support JC virus multiplication.
2. Description of the Prior Art
Glial cells derived from a normal, human fetal brain have a very limited life span once placed in cell culture for laboratory investigation.
There are several examples of normal fetal glial cells established in culture derived from experimental laboratory animals such as the rat (Shipiro, 1983, Nature 241: 203-204 and chickens (Giott et al, 1983, in "Neurosciences: Approaches and Tissue Culture", pages 203-225 Ed. Steven Pfeiffer, C.R.C. Press, Boca Raton, Fla.). There are also several human cell cultures which are able to propagate indefinitely in cell culture as cited by Maranda et al 1983 Proc. Natl. Acad. Sci. USA 80, 6581-6585. However, in each of these cases, there are serious limitations. In the case of the fetal rat brain, for example, the cells are, obviously, not of human origin eliminating their use as hosts for human viral pathogens restricted for growth to human cells and also, for the same reason, may not serve as good models for basic research experiments on human brain cells. Human brain cells which grow in culture have been derived from adult brain. These cells were neither fetal in their stage of development nor normal since they were derived from cases of multiple sclerosis, or Creutzfeldt-Jacob brain specimens as described by Santoli et al, 1975, J. Comp. Neurol. 161, 317-328. There is one report of human fetal glial cells transformed to grow rapidly in culture using infectious SV40 virus as described by Schein 1967, Neuropathol. Exp. Neurol. 26, 60-76. Although these cells were not tumorigenic, they gradully died out during cultivation due to cytolytic effects of SV 40 virus production. Further, these cells were also not as sensitive to other human viral pathogens as human cells already available for use.